In U.S. Pat. No. 4,715,399, a liquid-propellant management system is described, which can deliver substantially gas-free liquid propellant from a gas-pressurized storage tank to thrusters of a spacecraft without interruption during rapid changes in speed and/or direction of the spacecraft.
In U.S. Pat. No. 4,733,531, a technique involving capillary pumping vanes is described for collecting liquid propellant from remote regions of a gas-pressurized storage tank on a spacecraft to a trap positioned adjacent an outlet of the tank from which the liquid propellant is withdrawn from the tank for delivery to thrusters of the spacecraft.
Prior to the present invention, an unsolved problem in liquid-propellant management for spacecraft had been to minimize adverse effects on attitude stability of the spacecraft due to migration of liquid-propellant within an on-board storage tank.